【英文标准名称】:StandardTestMethodforAcidandBaseNumberbyColor-IndicatorTitration
【原文标准名称】:用颜色指示剂滴定法测定酸碱值的标准试验方法
【标准号】:ASTMD974-2008e1
【标准状态】:现行
【国别】:美国
【发布日期】:2008
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:D02.06
【标准类型】:(TestMethod)
【标准水平】:()
【中文主题词】:
【英文主题词】:acidnumber;basenumber;colorindicationtitration;petroleumproducts;Acidity,alkalinity,pH--petroleumproducts;Acidnumber--petroleumproducts;Color--petroleumproducts;Color-indicatortitration;Neutralizationnumbers
【摘要】:Newandusedpetroleumproductscancontainbasicoracidicconstituentsthatarepresentasadditivesorasdegradationproductsformedduringservice,suchasoxidationproducts.Therelativeamountofthesematerialscanbedeterminedbytitratingwithacidsorbases.Thisnumber,whetherexpressedasacidnumberorbasenumber,isameasureofthisamountofacidicorbasicsubstances,respectively,intheoilalwaysundertheconditionsofthetest.Thisnumberisusedasaguideinthequalitycontroloflubricatingoilformulations.Itisalsosometimesusedasameasureoflubricantdegradationinservice;however,anycondemninglimitsmustbeempiricallyestablished.Sinceavarietyofoxidationproductscontributetotheacidnumberandtheorganicacidsvarywidelyincorrosiveproperties,thetestcannotbeusedtopredictcorrosivenessofanoilunderserviceconditions.Nogeneralcorrelationisknownbetweenacidnumberandthecorrosivetendencyofoilstowardmetals.Compoundedengineoilscanandusuallydohavebothacidandbasenumbersinthistestmethod.1.1Thistestmethodcoversthedeterminationofacidicorbasicconstituents(Note1)inpetroleumproductsandlubricantssolubleornearlysolubleinmixturesoftolueneandisopropylalcohol.Itisapplicableforthedeterminationofacidsorbaseswhosedissociationconstantsinwaterarelargerthan10x2212;9;extremelyweakacidsorbaseswhosedissociationconstantsaresmallerthan10x2212;9donotinterfere.Saltsreactiftheirhydrolysisconstantsarelargerthan10x2212;9.Note18212;Innewandusedoils,theconstituentsconsideredtohaveacidiccharacteristicsincludeorganicandinorganicacids,esters,phenoliccompounds,lactones,resins,saltsofheavymetals,andadditionagentssuchasinhibitorsanddetergents.Similarly,constituentsconsideredtohavebasicpropertiesincludeorganicandinorganicbases,aminocompounds,saltsofweakacids(soaps),basicsaltsofpolyacidicbases,saltsofheavymetals,andadditionagentssuchasinhibitorsanddetergents.Note28212;Thistestmethodisnotsuitableformeasuringthebasicconstituentsofmanybasicadditive-typelubricatingoils.TestMethodD4739canbeusedforthispurpose.1.2Thistestmethodcanbeusedtoindicaterelativechangesthatoccurinanoilduringuseunderoxidizingconditions.Althoughthetitrationismadeunderdefiniteequilibriumconditions,themethoddoesnotmeasureanabsoluteacidicorbasicpropertythatcanbeusedtopredictperformanceofanoilunderserviceconditions.Nogeneralrelationshipbetweenbearingcorrosionandacidorbasenumbersisknown.Note38212;Oils,suchasmanycuttingoils,rustproofingoils,andsimilarcompoundedoils,orexcessivelydark-coloredoils,thatcannotbeanalyzedforacidnumberbythistestmethodduetoobscurityofthecolor-indicatorendpoint,canbeanalyzedbyTestMethodD664.Theacidnumbersobtainedbythiscolor-indicatortestmethodneednotbenumericallythesameasthoseobtainedbyTestMethodD664,thebasenumbersobtainedbythiscolorindicatortestmethodneednotbenumericallythesameasthoseobtainedbyTestMethod